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Stump on why this statement ever performs well 1 day 5 minutes next day a second.

  • January 27, 2011 at 9:03 am

    #1279140

    shaun.stuart,

    I ment a column...for example by taxid, customerid or another unique value that has an index.

    The following script was the one they ran to rebuild the index.

    EXEC sp_updatestats 'resample'

    EXEC sp_MSforeachtable @command1="print '?' DBCC DBREINDEX ('?', ' ', 80)"

    Needless to say that the to results where unsuccessful. The success was that the issue has now been submited to programming.

    Thanks again everyone.

  • January 27, 2011 at 9:31 am

    #1279159

    Please see the attached actual execution plans. One useing the address search and the other useing a taxid search.

    The address search tool around 5 minutes the taxid search took about 1 second.

    Thanks again. I just wanted to add that last bit of information that was asked for on this post.

  • January 27, 2011 at 11:00 am

    #1279244

    Carlton B Ramsey (1/27/2011)

    Please see the attached actual execution plans. One useing the address search and the other useing a taxid search.

    The address search tool around 5 minutes the taxid search took about 1 second.

    Thanks again. I just wanted to add that last bit of information that was asked for on this post.

    Now that's easy to answer:

    The taxid query used a nonclustered index seek whereas the address search needed a table scan due to the non-sargable WHERE clause.

    So it looks like the source is a dynamic query that'll use different columns if needed.

    To answer your original question: the reason for being slow on one day and fast on the next day might be caused by an alternating dynamic query.


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